As high strength stainless steels having a tensile strength of the order of 100 kgf/mm.sup.2 or more, there are known work hardened austenitic stainless steels, low carbon martensitic stainless steels and precipitation hardened stainless steels. These stainless steels, because of their excellent fatigue properties, corrosion resistance and heat resistance, are widely used for the production of steel belts and various springs. Such materials for steel belts and processes for the production of a steel belt are disclosed in, for example, JP B 51-31085 and JP B 61-9903.
Work hardened austenitic stainless strips are prepared by processes comprising cold rolling a metastable austenitic stainless strip to impart work induced strain and tempering the cold rolled strip. Whereas low carbon martensitic stainless steel strips are prepared by processes comprising quenching a strip of low carbon, Cr-Ni stainless steel whose chemical composition has been adjusted so that the steel has a lath martensitic structure at ambient structure from an annealing temperature which is normally 900.degree. C. or higher. In any event, in order to produce a stainless steel strip of having a good shape, the production process must include a final rolling step for shape rectification in which a rolling machine equipped with large diameter rolls is used. This step of rolling for shape rectification should be appropriately carried out, while carefully selecting conditions including, for example, rolling reduction, diameters of rolls and rate of rolling, depending upon the steel species, thickness of the strip and histories of the precedent production steps, or otherwise a flat stainless steel strip cannot be obtained and the production yield is reduced. Accordingly, it is eagerly desired to prepare a stainless steel strip excellent in flatness without the rolling step for shape rectification. Unfortunately, the desired technology is not yet established on the concerned steel species.